US671278A - Electrically-controlled switch. - Google Patents

Description

No. 67|,278. Patented Apr. 2, l90l. E. II. HEWLETT.

ELECTRICALLY CONTROLLED SWITCH.

I (Application filed Dec. 80, 1898.\ (No Model.) 3 Sheets-Sheet I.

hM-z N r u Edward M.}{ew l e'l't'. M 1

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E. n. HEWLETT.

ELECTRICALLY CONTRULLED SWITCH.

; 3 (Application Med Dec. :10. 1898.)

(No Model.) 3 Sheets-Shoot 2.

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YHE Nomus PEYERS co. Pno'ruu'rua. WASHINGTON. a. c

No. 67I,278. Patented Apr. 2. IBM.

E. M. HEWLETT.

ELECTRIGALLY CONTROLLED SWITCH.

(Applicltion fllsd Dec. 30, 1898.) (No Model.) 3 Shoots-$heet 3.

l E W T WH M e 5 m T w 8 m UNITED STATES PATENT @EEIo.

EDWARD M. HEWLETT, OF SCHENECTADY, NEW YORK, ASSIGNOR TO.TI-IE GENERAL ELECTRIC COMPANY, OF NEW YORK.

'ELECTRlCALLY-CONTRQLLED SWITCH.

SPECIFICATION forming part of Letters Patent No. 671,278, dated April 2, 1901.

Application filed December 30, 1898. Serial No. 700,710. No model.)

To a/ZZ whom it may concern:

Be it known that I, EDWARD M. HEWLETT, a citizen of the United States, residing at Schenectady, in the county of Schenectady, State of New York, have invented certain new and useful Improvements in Electrically-Controlled Switches, (Case No. 650,) of which the following is a specification.

My present invention relates to electrically-controlled switches such as are used, for example, for junction-boxes of underground systems, by which a branch circuit is connected to the main or feeder circuit by apparatus operated from a distance.

The particular type of switch which I have constructed consists in its essential features of a rotary motor, which bya system of gearing not only operates the circuit connections, but also throws a switch by which it is cut out of circuit after its office has been performed and a new circuit established by means of which the motor may be again operated for a certain definite time, again shifting its own circuit and operating, the connections as before. The opening of the motoreircuit is effected by a double-acting snapswitch having a quick break in both directions. Inasmuch as the usual underground systems are adapted only for moderate or low potentials no arc-extinguishingmeans is provided for any of the different contacts to be made or broken; but nothing in my invention limits me in this regard, as any usual device for this office might be added without invention. Not only does the motor thus control its own circuit, so that its operation is suspended after a certain time, out it is mechanically connected to the gearing by means of a loose connection or clutch, so that after a certain length of time, even should the motor continue to run by momentum, its operative connection with the gearing will be broken until the circuit is again established through the motor. In the circuit of the motor is a device by means of which the operative connection between the motor and gearing will be again reestablished as soon as ourrent-flow is established in the motor. In addition to the loose connection between the motor and the gears there is also a lost-motion connection between the gear and the circuit-breaker, operative in one direction only, the arrangement of this being such that if for any reason the usual springs should fail to open the circuit the continued motion of the motor would positively open the circuitbreakers to a sufficient distance to prevent arcing.

The circuit-mains are employed to convey current to the motor, and a single auxiliary line is run from the point at which the motor is to be controlled to the junction-box. In this line I prefer to arrange some sort of a testing device or indicator, by preference an incandescent lamp, which shall be of such high resistance that when it is in circuit sufficient current will not flow to start the motor. A switch is arranged by which the indicator may be cutout of circuit, and sufficient current then flows to rotate the motor until its cycle of operations is performed.

The accompanying drawings show a junction-box and its inclosed mechanism in which my invention has been embodied.

Figure I is a plan of a box. Fig. 2 is a section of a part of the boX upon the line 2 2 of Fig. 1. Fig. 3 is an enlarged detail of the connection between the motorand thccircuitbreakers, and Fig. 4 is a diagram of the circuits.

In Figs. 1 and 2, A is the frame of the box, which, as usual, is made of an integral casting.

B in Fig. 2 shows one of the main cables.

C is a slab, of slate or other substantial insulating material, to which the terminals B B &c., of the circuit-breakers are affixed. Cables B 13 enter the box through the glands B. The cables end in metal terminals E, which are secured in place by the bolts F F. Each pair of terminals B is connected by a bridge D, formed of a number of strips of good conducting metal, so as to have a limited flexibility, and an additional set of con tacts d is closed by a strip D. These latter contacts are preferably of carbon, for wellknown reasons. The bridge is carried upon a pin H, moving in a guide G, supported by a bar G, the latter being of insulating material. There are two of the circuitbreakers, one for each side of the system. They are Pins guides.

H H keep the bar in position and act as Springs 0 0 open the circuit when the gear is rotated to the proper posit-ion, as presently to be described. The motor R (see Figs. 1 and 3) is provided with a worm R meshing with the gear N. A can) M, operated by the gear, buthaviug a separable connection therewith, acts through the medium of the pawl Q to throw the contact P from one to the other of the contacts K K as the gear rotates. The cam also carries a pin L connecting the arm to the plate L on the under side of the insulating-bar I, the rotation of the cam acting to open and close the circuit-breakers. A lost-motion device is also provided, as presently to be described.

Referring now more particularly to Fig. 3, the end of the motor-shaft has a ratchet R" fast to the motor-shaft, registering with a similar ratchet on the end of a loose sleeve which carries the worm B A collar R is secured to the shaft, and a pin slides in the collar as the latter rotates, the pin being fast to the lever P. A suitable spring R" acts to force the ratchets into engagement. As the gear N rotates a lug N upon it engages with the end of the lever B and draws the ratchets out of engagement. The lever B is in turn fast to the armature S of an electromagnet S, having the yoke S and the spring S together with an adjustment S by which the position of the lever B may be varied as required.

The device for giving the snap action to the circuitbreakers will be best understood from Figs. 1 and 2. Referring more particularly to Fig. 2, Visa stud which carries the cam M and upon which rotates the gearwheel N, the latter being loose on a sleeve turning on the stud, but keyed to the arm U. W is a part of the frame forming a front bearing for the sleeve-carrying cam M. On the back of the gear is a lug n, registering with the arm U, keyed to the stud V, the arm thus being rigid with the cam M. The lug n has only contact with the arm U, so that the arm is free to move in one direction, but not in the other. The pawl Q; is pivoted on the stud P, which is fixed to a part of the frame \V of the apparatus. This pawl is provided with a too, which is operated by the walls of the notch in the cam M. The spring Q acts to throw the pawl in one direction-that is, to the right toward the contact K-and the cam throws the pawl in the opposite direction, maintaining it against the opposite contact K until the cam has made its complete revolution to nearly the illustrated position, in which the toe remains in engagement with the shoulderm. An instant later it is released, the spring Q carrying the contact P back to the contact K. The springs O 0 being much stronger than the spring Q when the loose connection between the cam M and the gears is actuated the latter spring is immediately overpowered. The device is thus a doubleacting snap switch, breaking the circuit quickly and positively in both directions of its movement. The operation of this part of the device is as follows: lVhen the motor rotates, the gear is turned in the direction of the arrow. (See Figs. 1 and The cam is thus rotated, and when the stud L passes the center the springs O 0 force down the bar I, and with it the link L, the arm U snapping away from the lug n on the back of the geai-N.

Referring now to Fig. 4-, the circuits of the apparatus may be readily traced. 1 2 are the circuit-mains, and 3 l are the leads from them to the terminals of the switch T. In the illustrated position the circuit of the motor is open, as will be seen by tracing from the lead 3 through the motor to the contact P, then by lead K, wire 6, and electromagnet S, the circuit as thus traced starting from the minus main and returning to the same side, so that no current. flows. The ratchet R" is also out of engagement, as illustrated.

If new it be desired to open the circuitbreakers, the switch T would be thrown to connect with the plus side of the circnit,wheu current would pass through the motor from the positive to the negative side over the circuit thus traced, the armature S of the electromagnet S would be attracted, releasing the bar R, the ratchet would come into engage.- ment, and the motor would rotate by current until the cam M engaged with the pawl Q, throwing the contact P to the other side of the circuit, where it would engage with the contact K and the lead 7. The circuit would thus be broken, but the motor would continue to run by momentum for a short time. As soon as the circuit was broken the bar It would be brought into the path of the lug N (see Fig. and the ratchet would be disengaged, so that after the circuit was established on the other side in readiness for a new im pulse of current the motor would cease to turn the worm R and the device would quickly stop.

In the lead 5 from the switch T is a lamp 8, controlled by the switch T. As already pointed out, it is designed to have the lamp of such high resistance that not enough current could flow to start the motor. \Vhen the switch is thrown from one side to the other, it serves to show whether the connec tions are in proper shape for the operation of the motor, which may be then thrown into action by the switch T, shunting the lamp and of ample current-ca1.'ryii1g capacity.

\Nhat I claim as new, and desire to secure by Letters Patent ol the United States, is

1. A motor-operated switch, comprising a driving electric motor operative always in the same direction, a gear, a clutch connecting the two, means for disconnecting the same after a definite range of movement, a twoway circuit-controller in the motor-circuit, a lostmotion connection between the same and the gear, and a control-circuit having connections with the two contacts of the two-way switch.

lTO

ether/8 2. The combination with a circuit-controlling device of a motor rotating always in one direction, a gear, a lost-motion connection between the gear and the circuit-controller, a clutch with the motor disconnected after a determined range of movement, and a switch operated by the connection for opening the motor-circuit and reestablishing it to the opposite main.

3. In a junction-box, means for opening and closing the connection between branch and main lines, a motor rotating in one direction only, a gear, a lost-motion connection between the gear and the circuit-breakers, a clutch with the motor disconnected after a determined range of movement, and a doubleacting snap-switch operated by the connec tion for opening the motor-circuit and reestablishing it to the opposite main.

4. The combination of a motor rotating in one direction only, a switch opened and closed thereby, a gear operated by the motor, atwoway switch for the motor operated by the gear, a clutch between the gear and the motor, means for throwing the clutch out of action by the rotation of the gear to a definite position, and a control-circuit having connections with the points of the two-way switch.

5. The combination of a motor, a gear, cireuit-breakers operated by the gear, a snapswitch for opening the motor-circuit, a clutch between the gear and the motor, a stud on the gear for disengaging the clutch at a eertain definite position, a switch at a desired point for restablishing the motor-circuit, and means for reengaging the clutch when the motor-circuit is established.

6. The combination of a motor, a gear, a clutch between the motor and the gear, a lever connected to the clutch, a stud on the gear for operating the clutch at a definite position and disengaging the gear from the motor, circuit-breaking devices operated by the gear, a switch also operated by the gear for opening the motor-circuit at a definite position, another switch at a desired point for reestablishing the motor-circuit, and a magnet in the circuit of the second switch for disengaging the clutch-lever from the stud on the gear so that the clutch is again thrown into action.

'7. The combination of a motor, a circuitbreaking device, a clutch between the circuit-breaker and the motor, means for disengaging the clutch after a determined range of movement, means for opening the motorcircuit, and a magnet in the motor-circuitior reengaging the clutch whenever the motor circuit is established.

8. The combination of a motor, a doubleacting snap-switch connected to the motor so that at certain definite times the motor opens its owfi circuit, a clutch releasing the switch after a definite range of movement, and a control-switch at a desired point for reestablishing the motor-circuit.

9. I11 a switch, the combination of fixed contacts, vertically-movable contacts carried by a spring-actuated frame, a crank and motor driving the same to close the contacts, thereby straining the spring, and means for releasing the frame after a determinate range of m otor movement and permittingit to freely obey the spring.

In witness whereof I have hereunto set my hand this 28th day of December, 1898.

EDWARD M. HEWLETT.

Vfitnesses:

T. J. J OHNSTON,

3. B. HULL.

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